Although it still remains the bank's legal headquarters, its operational head office was moved to First Canadian Place in Toronto in 1977 due to political instability in Quebec.

The centrepiece of the complex is the Bank of Montreal Main Branch, a Pantheon-like building designed by John Wells in 1847.

The building was inspired by the design of the former headquarters of the Commercial Bank of Scotland in Edinburgh.

[3] Enlargements to the building were made in 1901–1905 by the New York City firm of McKim, Mead & White.

The museum is open during regular bank hours and admission is free.